Quantifying the Impacts of the 2020 Flood on Crop Production and Food Security in the Middle Reaches of the Yangtze River, China

Abstract

This study uses satellite imagery and geospatial data to examine the impact of floods over the main planting areas for double-cropping rice and grain crops in the middle reaches of the Yangtze River. During summer 2020, a long-lasting 62-day heavy rainfall caused record-breaking floods over large areas of China, especially the Yangtze basin. Through close examination of Sentinel-1/2 satellite imagery and Copernicus Global Land Cover, between July and August 2020, the inundation area reached 21,941 and 23,063 km2, and the crop-affected area reached 11,649 and 11,346 km2, respectively. We estimated that approximately 4.66 million metric tons of grain crops were seriously affected in these two months. While the PRC government denied that food security existed, the number of Grains and Feeds imported from the U.S. between January to July 2021 increased by 316%. This study shows that with modern remote sensing techniques, stakeholders can obtain critical estimates of large-scale disaster events much earlier than other indicators, such as disaster field surveys or crop price statistics. Potential use could include but is not limited to monitoring floods and land use coverage changes.

Estimation of Total Phosphorus Concentration in Lakes in the Yangtze-Huaihe Region Based on Sentinel-3/OLCI Images

“…In the Yangtze-Huaihe region, the TP concentrations in lakes exhibited a trend of being higher in spring and summer and lower in autumn and winter. This pattern may be related to the double-cropping rice planting system in which fertilisers are applied to the soil during both the spring and summer seasons [54], resulting in a significant inflow of nutrients into lakes [55]. For large lakes, the changing trend in TP concentrations after 2020, characterised by higher levels in summer and autumn and lower levels in spring and winter, is mainly attributed to the time required for the ecological water quality recovery process after the removal of enclosure aquaculture in 2019 [56].…”

Applications of satellite data for rapid inundation assessment - A case study in Thua Thien Hue province

“…The high spatial resolution of Sentinel-1 SAR images enables detailed mapping of flood extents, providing valuable information for flood risk management and disaster response efforts. This satellite has been used to detect and map inundation events in various regions around the world, including those affected by monsoon rains and typhoons [5]. The use of Sentinel-1 SAR in flood detection and mapping provides disaster response organizations with the timely and accurate information they need to respond effectively to affected communities [6].…”

The effects of climate extreme events on selected food crop yields in Sub-Saharan Africa

“…Empirical evidence showed that natural disasters negatively influence agricultural production [ 2 , [7] , [8] , [9] , 12 ]. [ 7 ] found in the Philippines that typhoons significantly decreased production and the losses are estimated at 12.5 million tonnes since 2001 [ 7 ].…”